choose the correct vocabulary – there are different generic vocabularies like Dublin Core, FOAF etc and specialized vocabulary like Dcat, Void etc. for creating catalogs. Dcat is designed for government data catalogs, so I choose VoID vocabulary, which is designed for single dataset provider. It uses generic vocabularies lke FOAF and DC as well.

Select suitable tools – Tools to edit the RDF document. There are plenty of them ,in this case and RDF editor, like the Rhodonite tool for RDF editing and browsing. But I couldn’t understand it well because of poor documentation and help. So I chose an online VoID editor from DERI Galway. Though the result is in Turtle format, there are tools to convert turtle document to RDF/XML format. Like this one online : RDF Validator/converter rdfabout.com

Creating the semantic grpah – first I am going to choose a dataset and add it to my catalog. To start with, I chose CrunchBase entry listed in linkeddata.org. Go to VoID editor and add the following details in it

Convert in to RDF/XML file(serialize) – copy the dataset details in turtle notation and go to RDF/XML converter tool. And paste the turtle notated content there and select input format as N-Triples/Turtle, and click validate. The result is given below.

And the catalog is ready in RDF/XML with all the datasets added. Save it as a file with extension .rdf like Linked_data_catalog.rdf. Now the machine can understand (if programmed wisely) to some extend what data are available there to convert in to meaningful information and then to knowledge. You can find the catalog here: Linkeddata datasets catalog(note: not yet ready, comeback later )

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Very nice post, good analysis of the tools and well explained. Some remarks:

1. The voiD editor ve2 has a new location (http://lab.linkeddata.deri.ie/ve2/) and would be great if this change is reflected. I don’t plan to further maintain or update the version on the old location.

2. As I already mentioned on Twitter, I think it would be more beneficial if you submit the voiD files you create to a voiD store such as http://void.rkbexplorer.com/ (btw, you can directly announce voiD files to stores and indexer in ve2) rather than maintaining a single huge document on your own. The reasons are manifold: stores scale and are community-driven, offer a SPARQL endpoint and a look-up facility.

3. It’s interesting to see that quite a number of your proposed steps deal with low-level formatting/syntax issues (RDF/XML, etc.) which are actually rather irrelevant in the broader context.

Thanks Michael for your valuable opinions
re: 1. VoID editor Link – I have modified the link .
2. About VoID store and seperate files – I will consider that for sure.
3. about low level syntax etc – Also I intend to give people a deeper insight in to the mechanisms. It sure can be automated duely.
The whole Linkeddata/semantic web/open data debate seems to be very confusing. So I started working on things rather than reading standard and articles,in order to get a clearer picture. So I am starting with the top most cataloging and then step-by-step in to its applications. Data conversion itself is a huge job to be done in order to realize the vision.
Glad that it is inviting expert interactions.

Anand, this is a great idea and I’d love to see the outcome, even if it doesn’t cover all of the datasets in the cloud! The resulting RDF could be easily combined with other voiD data collections to create a unified catalog of datasets.

Thanks for sharing your thoughts Richard.
The LoD graph visualization itself gives us enough information on how the data are connected to each other. So I thought to start working on a semantic graph of the same as the top most entry point to linked data.I am still working on it and some of the datasets are vaguely documented, that makes it difficult to catalog. I will definitely ping you once I finish with the work
Regards
Anand

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I belong to the geographic location called Kerala in India. Very passionate about science and technology. I believe that ability to design and use tools makes the man different from other animals.Technology is the latest tool of the mankind.I love to learn and teach these tools. I am trained to learn it and use it.